1. Field of the Invention
The present invention relates to a method for inspecting a honeycomb structured body and a method for manufacturing a honeycomb structured body.
2. Discussion of the Background
Harm to the environment and the human body caused by particulates such as soot contained in exhaust gas discharged from the internal combustion engines of buses, trucks and other vehicles, construction equipment and the like has recently become a problem. For this reason, there are currently proposed numerous kinds of honeycomb filters using a honeycomb structured body comprising porous ceramic as a filter for capturing particulates contained in exhaust gas, thereby purifying the exhaust gas.
FIG. 1 is a perspective view schematically showing an example of embodiments of such a honeycomb structured body. FIG. 2A is a perspective view schematically showing a honeycomb fired body which comprises the above-mentioned honeycomb structured body, while FIG. 2B is a cross-sectional view of the line A-A therein.
In a honeycomb structured body 130, a plurality of honeycomb fired bodies 140, of the kind shown in FIGS. 2A and 2B, are bound together by interposing a sealing material layer (an adhesive layer) 131 forming a ceramic block 133, and a sealing material layer (a coat layer) 132 is formed over the outer periphery of the ceramic block 133.
And comprising the honeycomb fired body 140 are, as shown in FIGS. 2A and 2B, a multitude of cells 141 placed in parallel with one another in the longitudinal direction, and cell walls 143, which partition the cells 141 individually, and provide filtration functionality.
More specifically, as shown in FIG. 2B, the end portion of either the exhaust gas inlet side or the exhaust gas outlet side of the cells 141 formed in the honeycomb fired body 140 is sealed by a plug material layer 142. Therefore, the exhaust gas which enters one cell 141 will always pass through the cell wall 143 dividing the cells 141, to flow out through another one of the cells 141. When the exhaust gas passes through the cell wall 143, particulates contained within the exhaust gas are captured by the cell wall 143, thereby purifying the exhaust gas.
Conventionally, when manufacturing such a honeycomb structured body 130, for instance, first a ceramic powder, a binder, and a liquid dispersal medium are combined to prepare a wet mixture. Using a die, the wet mixture is continuously extraction molded, and the extruded molded body is then cut to a prescribed length to manufacture a rectangular pillar-shaped honeycomb molded body.
Next, the honeycomb molded body attained above is dried, and afterward, plugs are injected into either end of prescribed cells using the plug material layer in order to achieve a sealed state of the cells. After the sealed state has been achieved, degreasing and firing treatment is carried out, thus manufacturing the honeycomb fired body.
Afterward, a sealing material paste is applied onto the sides of the honeycomb fired body, and the honeycomb fired bodies are adhered together using the sealing material paste. This state of a multitude of the honeycomb fired bodies being bound together by interposing a sealing material layer (the adhesive layer) effectuates an aggregated body of honeycomb fired body. Excision is then carried out on the achieved aggregated body of honeycomb fired bodies using a cutting machine or the like to achieve a ceramic block of a prescribed shape, such as a cylindrical or cylindroid shape or the like. Finally, a sealing material paste is applied over the outer periphery of the ceramic block to form a sealing material layer (the coat layer), thereby completing the manufacture of the honeycomb structured body.
The honeycomb structured body of the sort described herein above (ceramic filters or catalyst supporting carrier) is normally stored within a casing for use. Because of this, before storing the honeycomb structured body within the casing, it is necessary to inspect whether or not the manufactured honeycomb structured body has the prescribed shape fitting to the above-mentioned casing.
At this point, there is disclosed a method (Reference Patent Document 1 for instance) of, for instance, photographing the exterior shape (the end face) of the honeycomb structured body to acquire an original image, and applying image processing to this original image to measure the exterior shape of the honeycomb structured body as a method for inspecting the shape of the manufactured honeycomb structured body (see for example JP-A 2002-267427).
The contents of JP-A 2002-267427 are incorporated herein by reference in their entirety.